[[1]}, [2]}]

Let \(G = (V, E)\)  be a DAG, and \(S\subseteq E\) . A flow \(C: E \rightarrow \mathbb {N}\)  can be computed in \(O(mn)\)  time, such that \(C(e)\ge 1\)  for all \(e\in S\)  and \(|C|=\textsf {width}_S(G)\) .
